Back contact solar cell module, cell and patterned structure thereof

Abstract

The invention relates to the technical field of solar energy, and discloses a back contact solar cell module, a cell and a patterned structure thereof. In the patterned structure, the middle grid line comprises a first grid line and a second grid line, the first grid line comprises a plurality of first auxiliary grids with first connecting regions, and the second grid line comprises a plurality of second auxiliary grids with second connecting regions; in the first direction, the first connection areas are collinear, the second connection areas are collinear, and the first connection areas and the second connection areas are arranged in a staggered mode. The edge grid lines comprise first edge grid lines and / or second edge grid lines, the first edge grid lines are close to the second auxiliary grids and connected with part of the first auxiliary grids, and the second edge grid lines are close to the first auxiliary grids and connected with part of the second auxiliary grids. According to the invention, the middle grid line can shorten the carrier transmission distance of the grid line structure at the outermost edge, improve the collection efficiency, and meet the reliability requirements of solder strips and the like; the edge grid line improves the carrier collection performance of the edge area.

Description

Technical Field

[0001] This disclosure relates to the field of solar cell technology, specifically to back-contact solar cell modules, cells, and their patterned structures. Background Technology

[0002] Back-contact solar cells are a technology that moves the front-side grid lines to the back side, avoiding light loss caused by the front-side grid lines. Because grid lines of different polarities are located on the back side of the cell, the overall grid patterning scheme becomes particularly crucial. To facilitate the extraction of charge carriers from the back-contact solar cell, grid lines of different polarities are arranged in a crisscross pattern on the back side of the cell. The main grid connects to the sub-grids of the same polarity to collect the current on the sub-grids and ultimately conduct it. Furthermore, to facilitate cell performance testing and subsequent module connection, large pads (PADs) are typically placed on the main grid, concentrating all the current from the main grid onto the pads for subsequent probe bonding and solder ribbon connection.

[0003] However, in actual manufacturing processes, due to the need to consider carrier collection across the entire battery surface, both the main and auxiliary grid lines extend towards the battery edge. The limited space at the edge restricts the probe placement of the pads on the edge main grid during testing, and subsequent solder ribbons cannot be precisely pressed onto the battery edge. To improve this, in the relevant graphical design process, the pads are often shifted a certain distance towards the center of the battery, so that they are not aligned with the edge main grid on the same vertical line. The two are then interconnected via connecting lines, such as... Figure 1 As shown; however, such connection lines will also bring the problem of increased carrier transmission distance, thereby increasing current loss on the grid line, thus affecting battery performance and photoelectric conversion efficiency. Summary of the Invention

[0004] This disclosure provides a back-contact solar cell module, cell, and patterned structure thereof to solve the problem of poor carrier collection efficiency in current back-contact cell patterned structure designs, which affects cell performance and photoelectric conversion efficiency.

[0005] In a first aspect, this disclosure provides a patterned structure for a back-contact solar cell. The patterned structure is disposed on the back surface of a cell substrate and includes a central grid line and edge grid lines. The central grid line includes at least one set of first grid lines and at least one set of second grid lines. The first grid lines and second grid lines are alternately spaced along a second direction and have opposite polarities. The first grid lines include a plurality of first sub-grids spaced along a first direction, and the second grid lines include a plurality of second sub-grids spaced along a first direction. The first sub-grids and second sub-grids are alternately spaced. The first sub-grids include a first connection region for electrical conduction, and the second sub-grids... It includes a second connection area for electrical discharge, a plurality of first connection areas are collinearly arranged in a first direction and offset from the second sub-gate, and a plurality of second connection areas are collinearly arranged in a first direction and offset from the first sub-gate; the edge gate line includes a first edge gate line and / or a second edge gate line, the edge gate line is located on both sides of the middle gate line in a second direction and extends along the first direction, the first edge gate line is adapted to be disposed outside the second sub-gate of opposite polarity and connected to a portion of the first sub-gate, and the second edge gate line is adapted to be disposed outside the first sub-gate of opposite polarity and connected to a portion of the second sub-gate.

[0006] Beneficial effects: The central grid lines of the patterned structure can maximize the reduction of carrier transport distance in the outermost grid lines, improving their carrier collection efficiency, while also meeting the position and reliability requirements of the solder strip placement; while the edge grid lines are located beside the central grid lines in the second direction and are infinitely close to the edge of the battery substrate, thus maximizing carrier collection in the edge region of the battery substrate. Furthermore, the patterned structure disclosed herein is applicable to various types of batteries with and without grids, offering a wide range of applications.

[0007] In one alternative implementation, a first connection area on a first sub-gate forms a first connection point, and a second connection area on a second sub-gate forms a second connection point; in a first direction, the width of the first connection point is greater than the width of the first sub-gate, and the width of the second connection point is greater than the width of the second sub-gate.

[0008] Beneficial effects: Widening the first and second connection points facilitates the placement of solder pads and even solder strips, improving connection reliability and conductivity. The widths of the first and second connection points can be the same or different; it is preferred that the widths of the first and second connection points be the same to improve processing efficiency.

[0009] In one alternative embodiment, a plurality of extensions are provided on the side of the edge gate line facing the central gate line. The extensions extend in a second direction toward the sub-gates of the same polarity. The first part of the extension is connected to the corresponding sub-gate of the same polarity, and the second part of the extension has a gap space with the sub-gate of the same polarity. The gap space corresponds to the connection area of ​​different polarities in the first direction.

[0010] Beneficial effects: The edge grid line extending along the first direction has several extensions extending along the second direction on the side facing the central grid line. The number of extensions can be equal to the number of sub-grids of the same polarity on the central grid line. The extensions on the same edge grid line are divided into two parts. The first part of the extensions is directly connected to the sub-grids of the same polarity, which facilitates the discharge of charge carriers from the edge grid line. The second part of the extensions maintains a space between itself and the sub-grids of the same polarity. This space corresponds to the connection area of ​​sub-grids of different polarities. That is, while improving the collection of charge carriers in the battery, the second part of the extensions also ensures the isolation between the second part of the extensions and the sub-grid when pads or even solder strips are set on the sub-grids of opposite polarities, effectively ensuring the power generation performance of the battery.

[0011] In one alternative embodiment, it further includes: an insulating structure disposed on the extension of the first portion, and the insulating structure and the connecting area are correspondingly disposed in a first direction, the connecting area having opposite polarity to the extension of the first portion.

[0012] Beneficial effects: The insulating structure helps to further ensure isolation from sub-gates of different polarities when setting up solder pads and solder ribbons, ensuring effective output of charge carriers for the entire battery.

[0013] In an optional embodiment, it further includes: a first bridge region for connecting a plurality of adjacent sub-gates disposed adjacent to the insulating structure in a first direction and having the same polarity, wherein the polarity of the sub-gates is opposite to the polarity of the extension covered by the insulating structure.

[0014] Beneficial effect: A first bridge region is set between two or more sub-gates adjacent to the insulating structure in the first direction. The first bridge region and the gate line can be made of the same or different conductive paste. This ensures that even if the sub-gate adjacent to the insulating structure has poor contact between the protrusion of the insulating structure and the solder strip, the carriers collected by the sub-gate will still be transferred to the adjacent sub-gate through the first bridge region, thus ensuring the overall carrier collection and output of the battery.

[0015] In one alternative implementation, it further includes: The second bridge region is disposed between at least two adjacent connection regions of the same polarity along the first direction to connect at least two adjacent sub-gates, wherein at least one sub-gate containing a connection region is connected to an extension of the first portion of the same polarity. And / or, a third bridge region is disposed along the first direction between at least two adjacent connection regions that are adjacent to the outermost edge of the battery substrate and have the same polarity, so as to connect at least two adjacent sub-gates.

[0016] Beneficial effects: The second bridge area can disperse the current from the edge grid lines to the current after the middle grid lines, making the current more stable and avoiding excessive current value from affecting current output and battery performance; the third bridge area is located on the outermost side of the patterned structure of the battery in the first direction, which can improve the problem of poor solder strip overlap performance at the edge, effectively preventing problems such as offset and failure to overlap during the solder strip overlap process at the outermost edge of the battery at the module end, and ensuring current output efficiency.

[0017] In one optional embodiment, the first grid line further includes a first main grid, which is disposed on the straight line where the plurality of first connecting areas are located, to connect the plurality of first sub-grids arranged along the first direction; the second grid line further includes a second main grid, which is disposed on the straight line where the plurality of second connecting areas are located, to connect the plurality of second sub-grids arranged along the first direction. Among them, at least the main gate immediately adjacent to the edge gate line forms a cut-off space at the position where the edge gate line connects with the sub-gate of the same polarity.

[0018] Beneficial effects: In this disclosure, all main gates in the middle gate line or the outermost main gate are segmented, that is, a cut-off space is formed in the area where they overlap with the sub-gate or the extension of the sub-gate and the edge gate line. This ensures that the connection between the edge gate line and the adjacent sub-gate of the same polarity, as well as the connection between the sub-gate of the same polarity in the middle gate line, are not affected by the main gates of different polarities, thereby improving the carrier collection efficiency.

[0019] In one optional embodiment, it further includes: a first pad and a second pad, the first pad being disposed on the first main gate and adapted to connect the first gate line to an external structure, and the second pad being disposed on the second main gate and adapted to connect the second gate line to an external structure.

[0020] Beneficial effects: The first pad is located on the first subgate, which facilitates a reliable connection with the external solder strip and improves the collection and transport of charge carriers in the first subgate; the second pad is located on the second subgate, which also facilitates a reliable connection with the external solder strip and improves the collection and transport of charge carriers in the second subgate.

[0021] In one alternative implementation, when multiple sets of first and second grid lines are provided, in the second direction, the distance between the first connecting area and the second connecting areas on both sides is equal, and the distance between the second connecting area and the first connecting areas on both sides is equal.

[0022] Beneficial effects: The first and second connection areas are used for subsequent installation of the main grid, solder pads, or solder ribbons. In the second direction, the distance between the first connection area and the second connection areas on both sides is equal, and the distance between the second connection area and the first connection areas on both sides is equal. That is, regardless of whether the location is for installing the main grid, solder pads, or solder ribbons in a grid-connected cell or for installing solder pads or solder ribbons in a gridless cell, the distance between adjacent installation locations in the second direction is equal, ensuring efficient carrier transport throughout the cell substrate and improving the photoelectric conversion efficiency of the cell.

[0023] In one alternative implementation, the edge grid lines are either sub-grid type grid lines or main grid type grid lines.

[0024] Beneficial effects: The main gate grid line, serving as the primary current transmission channel, handles high current densities and connects to solder ribbons or copper wires. It requires low contact resistance and high mechanical strength, and its relatively large linewidth necessitates deep sintering to ensure the silver paste penetrates the passivation film and forms reliable ohmic contact with the doped region, reducing series resistance. The sub-gate grid line is suitable for collecting photogenerated carriers and transporting them to the main gate grid line, balancing high conductivity and low shading. Its finer linewidth requires shallow sintering to minimize damage to the silicon substrate and prevent excessive diffusion leading to increased surface recombination. The selection of different grid line types with varying linewidths and sintering depths allows for greater adaptability to different cell types when setting up edge grid lines.

[0025] In one alternative embodiment, the first sub-gate and the second sub-gate are arranged in a straight line; or the first sub-gate and the second sub-gate are arranged in a bend-turn shape; or the first sub-gate and the second sub-gate are arranged in a comb-like shape.

[0026] Beneficial effects: The linear sub-grid is easy to form, which helps to improve production efficiency in batch production; the bend-and-turn sub-grid can reduce the overlap of the main grid and the sub-grid, reduce unnecessary costs, and the main grid other than the reduced connection position can be appropriately shortened to provide more patterned design possibilities; the comb-shaped sub-grid has the design advantages of the bend-and-turn sub-grid, as well as the advantage of simple preparation, which helps to facilitate mass production.

[0027] Secondly, this disclosure also provides a back-contact solar cell, comprising: a cell substrate and the aforementioned patterned structure, wherein the cell substrate includes a light-receiving surface and a back-lighting surface disposed opposite to each other, and the patterned structure is disposed on the back-lighting surface of the cell substrate.

[0028] Beneficial effects: The back-contact solar cell has the aforementioned patterned structure. The central grid lines maximize the reduction of carrier transport distance at the outermost grid lines, improving carrier collection efficiency, while also meeting the position and reliability requirements of the solder pads and ribbons. The edge grid lines, located beside the central grid lines in the second direction and infinitely close to the edge of the cell substrate, maximize carrier collection in the edge region of the cell substrate, thereby improving the photoelectric conversion efficiency of the back-contact solar cell. Furthermore, the patterned structure disclosed herein is applicable to various types of back-contact solar cells, including those with and without main grids, offering a wide range of applications.

[0029] Thirdly, this disclosure also provides a back-contact solar cell module, including a plurality of the aforementioned back-contact solar cells and a plurality of solder strips, the solder strips being adapted to connect adjacent back-contact solar cells.

[0030] Beneficial effects: The above-mentioned back-contact solar cell module has multiple back-contact solar cells and all the beneficial effects of the above-mentioned back-contact solar cells, and has better application advantages at the module end. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a patterned structure for a back-contact solar cell in related technologies. Figure 2 This is a schematic diagram of a patterned structure used in a gridless structure according to an embodiment of the present disclosure. Figure 3 This is a schematic diagram of another structure when the patterned structure of this disclosure is used in a gridless structure. Figure 4 This is a schematic diagram of the patterned structure used in an embodiment of the present disclosure when a main grid structure is present. Figure 5 This is a schematic diagram of another structure of the patterned structure of this disclosure when used in a main grid structure; Figure 6 This is a partial structural diagram showing the sub-gates in a linear shape in the patterned structure of an embodiment of this disclosure; Figure 7 This is a partial structural diagram showing the sub-gate in a bend-turn shape in the patterned structure of an embodiment of the present disclosure; Figure 8 This is a partial structural diagram of the sub-gate in the patterned structure of an embodiment of the present disclosure, showing a comb-like shape.

[0033] Explanation of reference numerals in the attached figures: 100. Battery substrate; 1. Middle grid line; 101. First grid line; 1011. First sub-grid; 1011a. First connecting area; 1012. First main grid; 102. Second grid line; 1021. Second sub-grid; 1021a. Second connecting area; 1022. Second main grid; 201, First edge grid line; 202, Second edge grid line; 301, First pad; 302, Second pad; 401. First connection point; 402. Second connection point; 501, First extension; 501a, First extension of the first part; 501b, First extension of the second part; 502, Second extension; 502a, Second extension of the first part; 502b, Second extension of the second part; 601. First insulation structure; 602. Second insulation structure; 701. First Sub-bridge Area; 702. Second Sub-bridge Area; 703. Third Sub-bridge Area; 704. Fourth Sub-bridge Area; 801, First truncation space; 802, Second truncation space. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0035] like Figures 2 to 8As shown, an embodiment of this disclosure discloses a patterned structure for a back-contact solar cell. The patterned structure is disposed on the back surface of a cell substrate 100 and includes: a central grid line 1 and edge grid lines. The central grid line 1 includes at least one set of first grid lines 101 and at least one set of second grid lines 102. The first grid lines 101 and second grid lines 102 are alternately spaced along a second direction and have opposite polarities. The first grid lines 101 include a plurality of first sub-grids 1011 spaced along a first direction, and the second grid lines 102 include a plurality of second sub-grids 1021 spaced along a first direction. The first sub-grids 1011 and second sub-grids 1021 are alternately spaced. The first sub-grids 1011 include a first connection region 1011a for electrical conduction, and the second sub-grids 102a... 1 includes a second connection region 1021a for electrical discharge, a plurality of first connection regions 1011a are collinearly arranged in a first direction and offset from the second sub-gate 1021, and a plurality of second connection regions 1021a are collinearly arranged in a first direction and offset from the first sub-gate 1011; the edge gate line includes a first edge gate line 201 and / or a second edge gate line 202, the edge gate lines are located on both sides of the central gate line 1 in a second direction and extend along the first direction, the first edge gate line 201 is adapted to be disposed outside the second sub-gate 1021 with opposite polarity and connected to a portion of the first sub-gate 1011, and the second edge gate line 202 is adapted to be disposed outside the first sub-gate 1011 with opposite polarity and connected to a portion of the second sub-gate 1021.

[0036] The aforementioned battery substrate 100 includes a silicon substrate and a film layer structure formed on the silicon substrate. The patterned structure of the back contact solar cell specifically includes electrodes formed by its positive and negative grid lines. Both the positive and negative grid lines are disposed on the back surface of the battery substrate 100, thereby reducing the light-shielding loss of the light-receiving surface. The positive and negative grid lines can be formed by conductive paste through printing or other methods.

[0037] The grid line electrodes in the patterned structure disclosed herein are divided into central grid lines 1 and edge grid lines. The central grid line 1 includes multiple sets of first grid lines 101 and multiple sets of second grid lines 102 arranged at intervals along the second direction. Among the first grid lines 101 and the second grid lines 102, one of them is a positive grid line and the other is a negative grid line. Of course, depending on the size of the battery substrate 100, only one set of first grid lines 101 and one set of second grid lines 102 can also be provided. The first gate line 101 includes a plurality of first sub-gates 1011 spaced apart in a first direction and whose center points are located on the same straight line. The second gate line 102 includes a plurality of second sub-gates 1021 spaced apart in a first direction and whose center points are located on the same straight line. The first direction is perpendicular to the second direction. This helps to divide the first sub-gates 1011 into a plurality of first connection regions 1011a corresponding to the first direction, and the second sub-gates 1021 into a plurality of second connection regions 1021a corresponding to the first direction. This facilitates the subsequent setting of structures such as main gates, pads, and even solder strips for electrical discharge. In addition, the straight line containing the center of the plurality of first sub-gates 1011 and the straight line containing the center of the plurality of second sub-gates 1021 are a certain distance apart in the second direction. This arrangement allows the first sub-gates 1011 and the second sub-gates 1021 to be alternately arranged in the first direction, so as to fully realize carrier collection and transmission.

[0038] Based on this, this disclosure provides edge grids on both sides of the central grid line 1 located in the second direction. According to the polarity of the grid structure closest to the edge of the battery substrate 100 in the central grid line 1, edge grids with opposite polarity are provided. For example, if the grid structure closest to the edge of the battery substrate 100 in the central grid line 1 is the positive grid line, then the edge grid line provided outside the positive grid line is the negative edge grid line, and vice versa. Based on this, the edge grid lines are also divided into a first edge grid line 201 and a second edge grid line 202 with opposite polarities; one of them is the positive edge grid line, and the other is the negative edge grid line. In conventional schemes, gridless batteries collect carriers only by extending sub-grids along the second direction towards the edge of the battery substrate 100, and then export them through solder ribbons located relatively close to the central region, or as... Figure 1 In addition to the aforementioned sub-gate configuration, the main gate of the battery shown has a main gate connected to these sub-gates at the edge of the battery substrate 100. Finally, carrier collection and export are achieved by moving the pads and solder ribbons inward by a certain distance. Unlike conventional solutions, in this disclosure, the edge gate lines extend along the first direction and only collect carriers located in the smaller edge region. Then, through partial connection with sub-gates of the same polarity, the carriers of the edge gate lines are transferred to the sub-gates of the same polarity. This effectively reduces the carrier transmission distance in the sub-gates near the edge region in the central gate line 1, reducing transmission losses, while also ensuring sufficient collection of carriers in the edge region, thereby improving the photoelectric conversion efficiency of the battery.

[0039] In summary, the patterned structure disclosed herein divides the grid line electrodes into central grid lines 1 and edge grid lines. The grid line structure at the outermost edge in the second direction of the central grid line 1 has a certain distance from the edge of the battery substrate 100 in the second direction. This certain distance can be determined based on the distance between each grid line structure in the central grid line 1 in the second direction. It is usually smaller than the distance between grid line structures of different polarities in the central grid line 1 and larger than the width of a conventional grid line. The distance between grid line structures of different polarities can be represented by the distance between the positions where the solder ribbon is set. That is, under the premise of ensuring that the grid line structures of different polarities in the central part have the same distance and that there is still a certain blank area at the edge, the scheme of simply extending the sub-grid infinitely to the edge of the battery substrate 100 is abandoned. Instead, an edge grid line is set in the edge region to collect the charge carriers in the edge region, and then part of it is connected to the sub-grid of the same polarity to achieve the final export of charge carriers. In this configuration, the central grid line 1 can maximize the reduction of the carrier transport distance of the outermost grid line structure, thereby improving its carrier collection efficiency, while also meeting the position and reliability requirements of the solder pads and solder ribbons. The edge grid lines are located beside the central grid line 1 in the second direction, and can be single-sided or double-sided, approaching the edge of the battery substrate 100, thus maximizing carrier collection in the edge region of the battery substrate 100. Furthermore, the patterned structure of this disclosure is applicable to various types of batteries with and without main grids, offering a wide range of applications.

[0040] refer to Figure 2 and Figure 3 In one embodiment, a first connection region 1011a on the first sub-gate 1011 forms a first connection point 401, and a second connection region 1021a on the second sub-gate 1021 forms a second connection point 402; in a first direction, the width of the first connection point 401 is greater than the width of the first sub-gate 1011, and the width of the second connection point 402 is greater than the width of the second sub-gate 1021.

[0041] When the patterned structure of this disclosure is applied to a gridless battery, a first connection area 1011a on the first sub-gate 1011 forms a first connection point 401 with a width greater than that of the first sub-gate 1011 itself. Similarly, a second connection area 1021a on the second sub-gate 1021 forms a second connection point 402 with a width greater than that of the second sub-gate 1021 itself. That is, multiple first connection points 401 are collinearly arranged in the first direction, and multiple second connection points 402 are collinearly arranged in the first direction. In the second direction, the straight line containing multiple first connection points 401 is parallel to the straight line containing multiple second connection points 402, and the distance between the edge of the first sub-gate 1011 and the edge of the adjacent second connection point 402 is greater than or equal to zero. Figure 3 The distance between the dashed line a1 and the dashed line b1 is greater than or equal to zero, and the distance between the edge of the second sub-gate 1021 and the edge of the adjacent first connection point 401 is greater than or equal to zero, that is... Figure 3 The distance between the dashed line a2 and the dashed line b2 is greater than or equal to zero.

[0042] The widened first connection point 401 and second connection point 402 facilitate the placement of the solder strip, improving connection reliability and conductivity. The widths of the first connection point 401 and second connection point 402 can be the same or different; preferably, the widths of the first connection point 401 and second connection point 402 are the same to improve processing efficiency. It should be understood that the aforementioned first connection area 1011a and second connection area 1021a are merely small regions defined on the first sub-gate 1011 and second sub-gate 1021, while the first connection point 401 and second connection point 402 represent the actual optimized structure.

[0043] refer to Figures 2 to 4 In one embodiment, a plurality of extensions are provided on the side of the edge gate line facing the central gate line 1. The extensions extend in a second direction toward the sub-gates of the same polarity. The first part of the extension is connected to the corresponding sub-gate of the same polarity, and the second part of the extension has a gap space with the sub-gate of the same polarity. The gap space corresponds to the connection area of ​​different polarities in the first direction.

[0044] The edge grid line extending along the first direction has several extensions extending along the second direction on the side facing the central grid line 1, for example, refer to Figure 2The first extension 501 of the first edge grid line 201 extends to the left, and its number can be equal to the number of the first sub-grids 1011 of the middle grid line 1. The first extension 501 can also be divided into two parts. The first extension 501a of the first part is directly connected to the adjacent first sub-grid 1011, which facilitates the discharge of the edge grid line's charge carriers. The first extension 501b of the second part maintains a space interval with the adjacent first sub-grid 1011. This space interval corresponds to the second connection area 1021a of the second sub-grid 1021. That is, the first extension 501b of the second part improves the collection of charge carriers in the battery, and also ensures the isolation from the second sub-grid 1021 when the solder strip is set on the second sub-grid 1021, effectively ensuring the power generation performance of the battery. Similarly, the second extension 502 of the second edge grid line 202 extends to the right, and its number can be equal to the number of the second sub-grids 1021 of the middle grid line 1. The second extension 502 can also be divided into two parts. The second extension 502a of the first part is directly connected to the adjacent second sub-grid 1021, which facilitates the discharge of the edge grid line's charge carriers. The second extension 502b of the second part maintains a space interval with the adjacent second sub-grid 1021. This space interval corresponds to the first connection area 1011a of the first sub-grid 1011. That is, while improving the collection of charge carriers in the battery, the second extension 502b of the second part also ensures the isolation from the first sub-grid 1011 when the solder strip is set on the first sub-grid 1011, effectively ensuring the power generation performance of the battery.

[0045] refer to Figure 3 In one embodiment, the patterned structure further includes an insulating structure disposed on the extension of the first portion, wherein the insulating structure and the connecting area are disposed correspondingly in a first direction, and the connecting area has opposite polarity to the extension of the first portion.

[0046] To further ensure isolation from sub-gates of different polarities during subsequent solder strip placement, this disclosure provides an insulating structure, such as an insulating adhesive layer, on the extension of the first portion corresponding to the connection area. (Reference) Figure 3 A first insulating structure 601 is provided on the first extension 501a of the first part to ensure that the first extension 501a and the first edge gate line 201 of the first part are electrically isolated from the first sub-gate 1011 when solder strips are subsequently provided on the second sub-gate 1021; similarly, a second insulating structure 602 is provided on the second extension 502a of the first part to ensure that the second extension 502a and the second edge gate line 202 of the first part are electrically isolated from the second sub-gate 1021 when solder strips are subsequently provided on the first sub-gate 1011.

[0047] Continue to refer to Figure 3In one embodiment, the patterned structure further includes a first bridge region for connecting a plurality of adjacent sub-gates disposed adjacent to the insulating structure in a first direction and having the same polarity, wherein the polarity of the sub-gates is opposite to the polarity of the extension covered by the insulating structure.

[0048] The aforementioned insulating structure is typically higher than the sub-gate. This can lead to poor contact between the solder strip and the sub-gate located on both sides of the insulating structure in the first direction when subsequent structures such as solder strips are added, resulting in electrical connection failure and affecting the carrier output of the sub-gate. Therefore, this disclosure provides a first bridge region connecting two or more sub-gates adjacent to the insulating structure in the first direction. The first bridge region and the gate lines can use the same or different conductive pastes. This ensures that even if a sub-gate adjacent to the insulating structure experiences poor contact with the solder strip due to the protrusion of the insulating structure, the carriers collected by that sub-gate will still be transferred to the adjacent sub-gate through the first bridge region, guaranteeing the overall carrier collection and output of the battery.

[0049] Specifically, such as Figure 3 As shown, the first bridge region includes a first sub-bridge region 701 and a second sub-bridge region 702 with different polarities. The first sub-bridge region 701 is disposed on both sides of the second insulating structure 602 in the first direction, and is used to connect two adjacent first connection points 401 on each side that are adjacent to the second insulating structure 602, so that when solder strips are placed on the first gate line 101, the carriers in all the first sub-gates 1011 are successfully discharged. That is, the polarity of the first sub-bridge region 701 is consistent with that of the first gate line 101. The second sub-bridge region 702 is disposed on both sides of the first insulating structure 601 in the first direction, and is used to connect two adjacent second connection points 402 on each side that are adjacent to the first insulating structure 601, so that when solder strips are placed on the second gate line 102, the carriers in all the second sub-gates 1021 are successfully discharged. The polarity of the second sub-bridge region 702 is consistent with that of the second gate line 102.

[0050] Furthermore, in one embodiment, the patterned structure of this disclosure further includes: a second bridge region and / or a third bridge region, wherein the second bridge region is disposed along a first direction between at least two adjacent connection regions of the same polarity to connect at least two adjacent sub-gates, wherein at least one sub-gate containing a connection region is connected to an extension of a first portion of the same polarity; and the third bridge region is disposed along the first direction between at least two adjacent connection regions adjacent to the outermost edge of the battery substrate of the same polarity to connect at least two adjacent sub-gates.

[0051] Specifically, refer to Figure 3The second bridge region includes a third sub-bridge region 703 and a fourth sub-bridge region 704 with different polarities. The third sub-bridge region 703 is located on both sides of a certain first connection region 1011a in a first direction. It connects two or more adjacent first connection regions 1011a or first connection points 401 in a set of first grid lines 101 to achieve the connection between two or more adjacent first sub-grids 1011. One of the first sub-grids 1011 is connected to the first extension 501a of the first part with the same polarity. The third sub-bridge region 703 has the same polarity as the first grid line 101. The fourth sub-bridge region 704... The fourth sub-bridge region 704 is located on both sides of a second connection region 1021a in the first direction. It connects two or more adjacent second connection regions 1021a or second connection points 402 in a set of second grid lines 102 to achieve connection between adjacent second sub-grids 1021. One of the second sub-grids 1021 is connected to the second extension 502 of the first part with the same polarity. The fourth sub-bridge region 704 has the same polarity as the second grid line 102. Of course, the third sub-bridge region 703 and the fourth sub-bridge region 704 can be located in multiple sets of first grid lines 101 and second grid lines 102. The second bridge region can disperse the current flowing from the edge grid lines to the current flowing from the middle grid line 1, making the current more stable and preventing excessive current from affecting current output and battery performance.

[0052] Similarly, the third bridge region includes a fifth sub-bridge region and a sixth sub-bridge region (not shown in the figure) with different polarities. The fifth sub-bridge region is set in multiple sets of first grid lines 101 and is used to connect two or more first sub-grids 1011 located on the outermost side in the first direction. Here, the outermost side includes the upper outermost side and the lower outermost side. The polarity of the fifth sub-bridge region is the same as that of the first grid lines 101. The sixth sub-bridge region is set in multiple sets of second grid lines 102 and is used to connect two or more second sub-grids 1021 located on the outermost side in the first direction. The polarity of the sixth sub-bridge region is the same as that of the second grid lines 102. Here, the outermost side also includes the upper outermost side and the lower outermost side. The third bridge region is located on the outermost side of the patterned structure of the battery in the first direction, which can improve the problem of poor solder strip overlap performance at the edge and effectively prevent problems such as overlap misalignment and failure to overlap at the outermost edge of the solder strip at the module end, thus ensuring current conduction efficiency.

[0053] refer to Figures 2 to 4 When multiple sets of first grid lines 101 and second grid lines 102 are provided, in the second direction, the distance between the first connecting area 1011a and the second connecting areas 1021a on both sides is equal, and the distance between the second connecting area 1021a and the first connecting areas 1011a on both sides is equal.

[0054] The first connection area 1011a and the second connection area 1021a are areas subsequently used to set the main gate, or solder pads, or solder strips. Figure 2For example, in the second direction, the distances between the first connection region 1011a and the second connection regions 1021a on both sides are equal, that is, L2 and L3 are equal. Similarly, the distances between the second connection region 1021a and the first connection regions 1011a on both sides are equal, that is, L1 and L2 are equal. In other words, regardless of whether the location is for setting the main grid, pads, and solder ribbons in a grid-connected cell or for setting pads or solder ribbons in a gridless cell, the distances between adjacent mounting locations in the second direction are equal, that is, L1, L2, and L3 are equal. This ensures efficient carrier transport across the cell substrate 100 and improves the photoelectric conversion efficiency of the cell.

[0055] refer to Figure 4 and Figure 5 In one embodiment, the first gate line 101 further includes a first main gate 1012, which is disposed on the straight line of the plurality of first connection areas 1011a to connect the plurality of first sub-gates 1011 arranged along the first direction; the second gate line 102 further includes a second main gate 1022, which is disposed on the straight line of the plurality of second connection areas 1021a to connect the plurality of second sub-gates 1021 arranged along the first direction; a first pad 301 is adapted to be disposed on the first main gate 1012, and a second pad 302 is adapted to be disposed on the second main gate 1022; wherein, at least the main gate adjacent to the edge gate line forms a cut-off space at the position where the edge gate line connects with the sub-gate of the same polarity.

[0056] The patterned structure described above is also applicable to batteries with main grids, wherein the first grid line 101 includes a first main grid 1012 that connects a plurality of first sub-grids 1011 by connecting each of the first connection regions 1011a, and the second grid line 102 includes a second main grid 1022 that connects a plurality of second sub-grids 1021 by connecting each of the second connection regions 1021a.

[0057] In one embodiment, such as Figure 4 and Figure 5 As shown, the patterned structure of this disclosure also includes a first pad 301 and a second pad 302. The first pad 301 is disposed on the first main gate 1012 and is adapted to connect the first gate line 101 with the external structure. The second pad 302 is disposed on the second main gate 1022 and is adapted to connect the second gate line 102 with the external structure.

[0058] In one embodiment, such as Figure 4As shown, this disclosure further segments a first main gate 1012 and a second main gate 1022 located close to the edge of the central gate line 1. A first cut-off space 801 is formed in the area where the first main gate 1012 overlaps with the second extension 502a of the first part, and a second cut-off space 802 is formed in the area where the second main gate 1022 overlaps with the first extension 501a of the first part, to prevent electrical conduction between gate lines of different polarities. A first pad 301 is correspondingly provided on the first main gate 1012 of each segment, and a second pad 302 is provided on the second main gate 1022 of each segment.

[0059] In another embodiment, such as Figure 5 As shown, this disclosure further segments all the first main gates 1012 and all the second main gates 1022 in the central gate line. Correspondingly, all the second sub-gates 1021 on the straight line where the second extension 502a of the first part is located are interconnected. At this time, all the first main gates 1012 form a first cut-off space 801 in the area where they overlap with the corresponding second sub-gates 1021. All the first sub-gates 1011 on the straight line where the first extension 501a of the first part is located are interconnected. At this time, all the second main gates 1022 form a second cut-off space 802 in the area where they overlap with the corresponding first sub-gates 1011, which helps to further ensure the carrier collection of the central gate line 1 and the edge gate line.

[0060] In one embodiment, the aforementioned edge grid line is a sub-grid type grid line or a main grid type grid line.

[0061] First, the main grid line has a larger linewidth. As the main body for current collection and transmission, it requires high conductivity and mechanical stability to ensure reliable connection with the sub-grid and external conductors, rather than penetrating deep into the material. Its sintering focuses more on conductivity and adhesion, and does not require strong corrosion. Therefore, the paste for the main grid line is usually a non-corrosive or low-corrosive paste to prevent damage to the metallization or passivation layer of the battery. On the other hand, the sub-grid line has a thinner linewidth. On the one hand, it needs to penetrate the passivation and antireflection film on the silicon substrate, and on the other hand, it needs to form a silver-silicon alloy with the surface of the silicon substrate to achieve ohmic contact. That is, its sintering process requires precise control of the corrosion depth to ensure that the contact resistance is minimized. Therefore, a highly corrosive paste is usually used to efficiently achieve this process.

[0062] Furthermore, since the solder strips connecting the main grid lines at the module encapsulation end may be made of different metals such as copper or tin-plated copper, using highly corrosive pastes can cause electrochemical corrosion between different metals. Therefore, the corrosivity of the main grid line paste must be controlled to ensure compatibility. However, the edge grid lines in this disclosure do not need to be connected to the solder strips at the module encapsulation end, so either main grid lines or sub-grid lines can be used. The selection of grid line types with different linewidths and sintering depths allows for greater adaptability to different cell types when setting up the edge grid lines.

[0063] like Figure 6 As shown, in one embodiment, the first sub-gate 1011 and the second sub-gate 1021 are arranged in a straight line, which is simple to form and helps to improve production efficiency in batch production.

[0064] like Figure 7 As shown, in another embodiment, the first sub-gate 1011 and the second sub-gate 1021 are arranged in a bend-down shape. The number of connection points between the sub-gate and the main gate is reduced. Firstly, since the connection points between the main gate and the sub-gate often require extending the sub-gate to achieve full overlap with the main gate, resulting in additional slurry loss, the bend-down sub-gate structure can reduce the overlap slurry between the main gate and the sub-gate, reducing unnecessary costs. Secondly, the main gate beyond the reduced connection points can be appropriately shortened, such as... Figure 7 As shown, this provides more possibilities for patterned design.

[0065] like Figure 8 As shown, in another embodiment, the first sub-gate 1011 and the second sub-gate 1021 are arranged in a comb-like pattern. Similarly, the comb-like arrangement of the sub-gates can reduce the number of connection points between the sub-gates and the main gate, that is, reduce the amount of overlap paste between the main gate and the sub-gates, reduce unnecessary costs, and to a certain extent, allow for a more appropriate shortening of the main gate beyond the reduced connection points. Figure 8 As shown, it offers the advantage of more patterned design possibilities, and also has the advantage of simpler preparation compared to zigzag designs, which is conducive to mass production.

[0066] refer to Figures 2 to 8 The present disclosure also provides a back-contact solar cell, including: a cell substrate 100 and the patterned structure described above. The cell substrate 100 includes a light-receiving surface and a back-lighting surface disposed opposite to each other, and the patterned structure is disposed on the back-lighting surface of the cell substrate 100.

[0067] The back-contact solar cell has the aforementioned patterned structure. The central grid line 1 maximizes the reduction of carrier transport distance at the outermost grid line structure, improving carrier collection efficiency, while also meeting the position and reliability requirements of the solder pads or solder ribbons. The edge grid lines are located beside the central grid line 1 in the second direction and are positioned infinitely close to the edge of the cell substrate 100, thus maximizing carrier collection in the edge region of the cell substrate 100. Furthermore, the patterned structure disclosed herein is applicable to various types of back-contact solar cells, including those with and without main grids, offering a wide range of applications.

[0068] Further functional descriptions of the above structures are the same as those of the corresponding embodiments described above, and will not be repeated here.

[0069] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A patterned structure for a back-contact solar cell, said patterned structure being disposed on the back surface of a cell substrate, characterized in that, include: The central grid line includes at least one set of first grid lines and at least one set of second grid lines, the first grid lines and the second grid lines being alternately spaced along a second direction and having opposite polarities; the first grid lines include a plurality of first sub-grids spaced along a first direction, and the second grid lines include a plurality of second sub-grids spaced along the first direction, the first sub-grids and the second sub-grids being alternately spaced; the first sub-grids include a first connection region for electrical discharge, the second sub-grids include a second connection region for electrical discharge, the plurality of first connection regions being collinearly arranged in the first direction and offset from the second sub-grids, and the plurality of second connection regions being collinearly arranged in the first direction and offset from the first sub-grids; An edge gate line includes a first edge gate line and / or a second edge gate line; the edge gate lines are located on both sides of the central gate line in the second direction and extend along the first direction; the first edge gate line is adapted to be disposed outside the second sub-gate of opposite polarity and connected to a portion of the first sub-gate; the second edge gate line is adapted to be disposed outside the first sub-gate of opposite polarity and connected to a portion of the second sub-gate.

2. The patterned structure according to claim 1, characterized in that, A first connection area on the first sub-gate forms a first connection point, and a second connection area on the second sub-gate forms a second connection point; in the first direction, the width of the first connection point is greater than the width of the first sub-gate, and the width of the second connection point is greater than the width of the second sub-gate.

3. The patterned structure according to claim 1, characterized in that, The edge grid line is further provided with a plurality of extensions on one side toward the middle grid line. The extensions extend toward the sub-grids of the same polarity along the second direction. The first part of the extension is connected to the corresponding sub-grid of the same polarity, and the second part of the extension has a gap space with the sub-grid of the same polarity. The gap space corresponds to the connection area of ​​different polarities in the first direction.

4. The patterned structure according to claim 3, characterized in that, Also includes: An insulating structure is disposed on the extension of the first portion, and the insulating structure and the connecting area are disposed correspondingly in a first direction, wherein the connecting area has the opposite polarity to the extension of the first portion.

5. The patterned structure according to claim 4, characterized in that, Also includes: A first bridge region is used to connect a plurality of adjacent sub-gates that are disposed adjacent to the insulating structure in the first direction and have the same polarity, wherein the polarity of the sub-gates is opposite to the polarity of the extension covered by the insulating structure.

6. The patterned structure according to claim 3, characterized in that, Also includes: The second bridge region is disposed between at least two adjacent connection regions of the same polarity along the first direction to connect at least two adjacent sub-gates, wherein at least one sub-gate containing a connection region is connected to an extension of the first portion of the same polarity. And / or, a third bridge region is disposed along the first direction between at least two adjacent connection regions that are adjacent to the outermost edge of the battery substrate and have the same polarity, so as to connect at least two adjacent sub-gates.

7. The patterned structure according to any one of claims 1-6, characterized in that, The first gate line further includes a first main gate, which is disposed on the straight line where the plurality of first connecting areas are located, to connect the plurality of first sub-gates arranged along the first direction; the second gate line further includes a second main gate, which is disposed on the straight line where the plurality of second connecting areas are located, to connect the plurality of second sub-gates arranged along the first direction. Among them, at least the main gate immediately adjacent to the edge gate line forms a cut-off space at the position where the edge gate line connects with the sub-gate of the same polarity.

8. The patterned structure according to claim 7, characterized in that, Also includes: First solder pad and second solder pad, the first solder pad is disposed on the first main gate and is adapted to connect the first gate line with the external structure; The second pad is located on the second main gate and is suitable for connecting the second gate line with the external structure.

9. The patterned structure according to claim 1, characterized in that, When multiple sets of the first grid line and the second grid line are provided, in the second direction, the distance between the first connecting area and the second connecting areas on both sides is equal, and the distance between the second connecting area and the first connecting areas on both sides is equal.

10. The patterned structure according to claim 1, characterized in that, The edge grid lines are either sub-grid type grid lines or main grid type grid lines.

11. The patterned structure according to claim 1, characterized in that, The first sub-gate and the second sub-gate are arranged in a straight line; or the first sub-gate and the second sub-gate are arranged in a bend-turn shape; or the first sub-gate and the second sub-gate are arranged in a comb-like shape.

12. A back-contact solar cell, characterized in that, include: A battery substrate, the battery substrate comprising a light-receiving surface and a backlighting surface disposed opposite to each other; And the patterned structure according to any one of claims 1-11, wherein the patterned structure is disposed on the backlight surface of the battery substrate.

13. A back-contact solar cell module, characterized in that, include: The back-contact solar cells according to multiple claims 12; And multiple solder strips adapted to connect adjacent back-contact solar cells.

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